Rate controlling device

ABSTRACT

A device attached to a moving element for controlling the rate of motion of the moving element. Viscous material, such as silicone bouncing putty, is enclosed in a flexible envelope and force is applied thereto substantially equal to the driving force applied to the moving element. When the moving element is speeded up, the resistance applied by the flexible envelope increases greater than proportionally to the force exerted thereon due to the properties of the viscous material.

O United States Patent 11 1 1111 3,871,496

-Wigal 1 I 5] Mar. 18, 1975 [5 RATE CONTROLLING DEVICE 3,353,632 ll/l967 Perhach .1 l88/1 B [76] Inventor: Voorhis F. Wigal, PO. Box 1542, I

Jackson, Tenn 38301 Primary Exammer-Trygve M. Bllx I Assistant E.\'(1Hti)7l-'Chflfl$ E. Frankfort Flledi 1973 Attorney, Agent, or Firm-John R. Walker, Ill

[21] Appl. No.: 337,730

[57] ABSTRACT 52 U.S. c1. 188/268, 188/1 B A device attached to a moving element for Controlling [51] Int. Cl Fl6f 9/30 the rate of motion of the moving element viscous [58] Field of Search H 188/266 268 80 83 1 te rial, such as silicone bouncing putty, is enclosed in a flexible envelope and force is applied thereto substantially equal to the driving force applied to the moving [56] References Cited element. When the moving element is speeded up, the UNITED STATES PATENTS resistance applied by the flexible envelope increases greater than proportionally to the force exerted 2,833,347 5/1958 Terry 188/268 thereon due to the properties f the viscous materiaL 2,9l0,246 10/1959 Halt 188/268 3,l4l,523 7/1964 Dickie 188/268 3 Claims, 5 Drawing Figures PATENTEDMAR 8l975 3.871.486

FIGJ

1 RATE CONTROLLING DEVICE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to devices for controlling the rate of motion of moving elements.

2. Description of the Prior Art A preliminary patentability search revealed the following U.S. Pat. Nos: Elsner et al., 3,638,767; Greene, 3,254,741; Blake, 3,244,382; Sinisterra, 2,775,317; Pierce, 2,570,854; and Wasdell, 2,503,143. None of the above patents disclose or suggest the present invention.

All the known prior devices for controlling the rate of motion of a moving element by means of viscous ma terial such as silicone bouncing putty are disadvantageous in that they depend on sealing the viscous material in direct engagement with the moving element. Thus, the construction of the prior devices is relatively complex and, therefore, expensive.

SUMMARY OF THE INVENTION The present invention is directed towards overcoming the problems and disadvantages in previous devices for controlling the rate of motion of a moving element. The concept of the present invention is to provide a flexible envelope to enclose the viscous material to prevent loss and/or contamination of the viscous material. Thus, it is not necessary to seal the viscous material in direct engagement with the moving element. The construction of the present invention is, thereby, greatly simplified over the prior devices and the cost of the present invention is greatly reduced from that of the prior devices.

The device of the present invention includes a flexible envelope, means activated by the moving element for applying a force against the flexible envelope, and viscous material such as silicone bouncing putty enclosed within the flexible envelope. The viscous material firmly resists suddenly applied forces but not slowly applied forces. That is, the rate of flow of the viscous material increases less than proportionally with the force applied to it.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of one embodiment of the present invention.

FIG. 2 is a sectional view as taken on Line II-II of FIG. 1.

FIG. 3 is a sectional view of a second embodiment of the present invention.

FIG. 4 is a sectional view of a third embodiment of the present invention.

FIG. 5 is a sectional view of a fourth embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The first embodiment 11 of the rate controlling device of the present invention includes a flexible envelope 13, means 15 for applying a force against the flexible envelope 13, and viscous material 17 enclosed within the flexible envelope 13 which firmly resists suddenly applied forces but not slowly applied forces. The viscous material 17 is preferably a silicone elastic polymer compound commonly known as silicone bouncing putty and is best described in columns 3 and 4 of the Pierce reference, US. Pat. No. 2,570,854. It should be pointed out that silicone putty is only one example of an appropriate material, and that the material 17 may be any non-Newtonian thixotropic liquid (rate of flow increases slightly with shearing stress). The rate controlling device 11 of the present invention controls the rate of motion of a driven or moving element 19.

Referring to the first embodiment as shown in FIGS. 1 and 2 of the drawings, the flexible envelope 13 is annular and is positioned on the same axis as the moving element 19. In this embodiment, the flexible envelope 13 includes a face portion 21 and side portions 23. Means 15 for applying a force against the flexible envelope 13 comprises a roller means 25. The roller means 25 includes at least one but preferably two primary rollers 27 for contacting the face portion 21 of the flexible envelope 13. The primary rollers 27 have their axes perpendicular to the axis of the flexible envelope 13. The roller means 25 also includes at least one but preferablyfour auxiliary rollers 29 for contacting the side portions of the flexible envelope 13 to urge the flexible envelope 13 into engagement with the primary rollers 27. In other words, the envelope 13, which has been flattened by rollers 27, is aided in being returned to its original shape. The auxiliary rollers 29 have their axes parallel to but offset from the axis of the flexible envelope 13. The primary rollers 27 and the auxiliary rollers 29 are attached to a shaft 31 through a platform member 33. The platform member 33 includes transverse arms 35 on which the primary and auxiliary rollers 27, 29 are attached. The flexible envelope 13 is fixedly attached as by adhesive or the like to a shaft 37 through a plate-like member 39. Either of the shafts 31 or 37 may be the moving element 19. The shaft which is not the moving element 19 is non-rotatably mounted to structure not shown. To illustrate, assuming that the shaft 37 attached to the flexible envelope 13 through the plate-like member 39 is the moving element 19, when the moving element 19 is rotated the flexible envelope 13 is rotated with it and the roller means 25 is held stationary. When the moving element 19 is speeded up, the resistance applied by the flexible envelope 13 increases greater than proportionally to the force exerted on the flexible envelope 13 by the roller means 25 due to the properties of the viscous material 17 within the flexible envelope 13. Also, it should be pointed out that the rate controlling device 11 may be positioned intermediate the ends of two moving shafts and motion transferred between the two shafts through the rate controlling device 11.

Referring to the second embodiment 111 as shown in FIG. 3, the flexible envelope 113 is normally spherical and the driven element 119 comprises a rotor 141. A stationary outer drum 143 surrounds the rotor 141 and the flexible envelope 113 is caged between the rotor 141 and the outer drum 143 in a space less than its normal diameter thereby causing a force to act against the flexible envelope 113. In other words, when no force is applied against the flexible envelope 113, it maintains a spherical shape with a constant diameter but, when the flexible envelope is caged between the rotor 141 and the outer drum 143, a force is applied to the flexible envelope 113 causing its shape to be somewhat distorted and causing its diameter to be greater in some directions than in other directions. Thus, the rotor 14! and the outer drum 143 coact together to comprise the means for applying a force against the flexible envelope 113. As the speed of rotation of the rotor 141 is increased, the resistance applied by the flexible envelope 113 is increased greater than proportionally to the force exerted on the flexible envelope 113 by means 115 due to the properties of the viscous material 117 within the flexible envelope 113.

Referring to the third embodiment 211 of the present invention as shown in FIG. 4, the flexible envelope 213 is circular and the driven or moving element comprises a linear sliding member 245. The flexible envelope v213 rotates about a center axis 247 and contacts the linear sliding member 245. The linear sliding member 245 and the center axis 247 coact together to comprise the means for applying a force against the flexible envelope 213. As the linear speed of the sliding member 245 increases, the resistance applied by the flexible envelope 213 increases greater than proportionally to the force exerted on the flexible envelope by means 215 due to the properties of the viscous material 217 within the flexible envelope 213.

Referring to the fourth embodiment 311 as shown in FIG. 5, the flexible envelope 313 is circular and the driven or moving element comprises a rotating drum 349. The flexible envelope 313 rotates about a center axis 351 and contacts the rotating drum 349. The rotating drum 349 and the center axis 351 coact together to comprise the means for applying a force against the flexible envelope 313. As the speed of rotation of the drum 349 is increased, the resistance applied by the flexible envelope 313 is increased greater than proportionally to the force exerted on the flexible envelope 313 by means 315 due to the properties of the viscous material 317 within the flexible envelope 313.

Although the invention has been described and illustrated with respect to preferred embodiments thereof, it is not to be so limited since changes and modifications may be made therein which are within the full intended scope of the invention.

1 claim:

1. A device attached to a moving element for controlling the rate of motion of the moving element, said device comprising: a flexible envelope, means responsive to the moving element for applying a force against said flexible envelope including at least one primary roller for forcefully contacting the face of said flexible envelope causing the face of said flexible envelope to be flattened, said primary roller having its axis perpendicular to the axis of said flexible envelope, and including auxiliary means for contacting at least one side of said flexible envelope aiding said flexible envelope to return to its original shape after being flattened, said auxiliary means including at least one auxiliary roller'for contacting at least one side of said flexible envelope aiding said flexible envelope to return to its original shape after being flattened by said primary roller, said auxiliary roller having its axis parallel to the axis of said flexible envelope, viscous material enclosed within said flexible envelope which firmly resists suddenly applied forces but not slowly applied forces, said viscous material comprising a non-Newtonian thixotropic liquid, and said flexible envelope being annular and being positioned on the same axis as the moving element.

2. A device attached to a moving element for controlling the rate of motion of the moving element, said device comprising: a flexible envelope, said flexible envelope being annular and being positioned on the same axis as the moving element; roller means responsive to the moving element for applying force against said flexible envelope, said roller for applying force against said flexible envelope, said roller means including at least one primary roller for forcefully contacting the face of said flexible envelope causing the face of said flexible envelope to be flattened, said primary roller having its axis perpendicular to the axis of said flexible envelope, said roller means including at least one auxiliary roller for contacting at least one side of said flexible envelope aiding said flexible envelope to return to its original shape after being flattened by said primary roller, said auxiliary roller having its axis parallel to the axis of said flexible envelope; and a non-Newtonian, thixotropic liquid enclosed within said flexible envelope which firmly resists suddenly applied force but not slowly applied force.

3. A device attached to a moving element for controlling the rate of motion of the moving element, said device comprising: a flexible envelope attached to the moving element, said flexible envelope being annular and being positioned on the same axis as the moving element, said flexible envelope having a face portion and side portions; roller means responsive to the moving element for applying a force against said flexible envelope, said roller means including a pair of primary rollers for forcefully contacting the face of said flexible envelope causing the face of said flexible envelope to be flattened, said primary rollers having their axes perpendicular to the axis of said flexible envelope, said roller means including at least one auxiliary roller for contacting each of the sides of said flexible envelope aiding said flexible envelope to return to its original shape after being flattened by said primary rollers, said auxiliary rollers having their axes parallel to the axis of said flexible envelope; and a non-Newtonian, thixotropic liquid enclosed within said flexible envelope which firmly resists suddenly applied force but not slowly applied force. 

1. A device attached to a moving element for controlling the rate of motion of the moving element, said device comprising: a flexible envelope, means responsive to the moving element for applying a force against said flexible envelope including at least one primary roller for forcefully contacting the face of said flexible envelope causing the face of said flexible envelope to be flattened, said primary roller having its axis perpendicular to the axis of said flexible envelope, and including auxiliary means for contacting at least one side of said flexible envelope aiding said flexible envelope to return to its original shape after being flattened, said auxiliary means including at least one auxiliary roller for contacting at least one side of said flexible envelope aiding said flexible envelope to return to its original shape after being flattened by said primary roller, said auxiliary roller having its axis parallel to the axis of said flexible envelope, viscous material enclosed within said flexible envelope which firmly resists suddenly applied forces but not slowly applied forces, said viscous material comprising a non-Newtonian thixotropic liquid, and said flexible envelope being annular and being positioned on the same axis as the moving element.
 2. A device attached to a moving element for controlling the rate of motion of the moving element, said device comprising: a flexible envelope, said flexible envelope being annular and being positioned on the same axis as the moving element; roller means responsive to the moving element for applying force against said flexible envelope, said roller for applying force against said flexible envelope, said roller means including at least one primary roller for forcefully contacting the face of said flexible envelope causing the face of said flexible envelope to be flattened, said primary roller having its axis perpendicular to the axis of said flexible envelope, said roller means including at least one auxiliary roller for contacting at least one side of said flexible envelope aiding said flexible envelope to return to its original shape after being flattened by said primary roller, said auxiliary roller having its axis parallel to the axis of said flexible envelope; and a non-Newtonian, thixotropic liquid enclosed within said flexible envelope which firmly resists suddenly applied force but not slowly applied force.
 3. A device attached to a moving element for controlling thE rate of motion of the moving element, said device comprising: a flexible envelope attached to the moving element, said flexible envelope being annular and being positioned on the same axis as the moving element, said flexible envelope having a face portion and side portions; roller means responsive to the moving element for applying a force against said flexible envelope, said roller means including a pair of primary rollers for forcefully contacting the face of said flexible envelope causing the face of said flexible envelope to be flattened, said primary rollers having their axes perpendicular to the axis of said flexible envelope, said roller means including at least one auxiliary roller for contacting each of the sides of said flexible envelope aiding said flexible envelope to return to its original shape after being flattened by said primary rollers, said auxiliary rollers having their axes parallel to the axis of said flexible envelope; and a non-Newtonian, thixotropic liquid enclosed within said flexible envelope which firmly resists suddenly applied force but not slowly applied force. 